Certain types of electric motors are manufactured or assembled by forming a stator of a series o f stator plates stacked together to form a laminated body. An example is a permanent magnet brushless DC motor. In some instances, the laminations are permanently bonded to one another to form a rigid, solid body or core. In other instances, the laminations are assembled in a loose array for subsequent repositioning. In either instance, the motor field windings then are installed, usually in axially extending slots in the wall of a bore through the stator. This stator then is attached to a frame or installed within a housing of the motor with the bore through the stator receiving a rotor attached to a shaft journalled in the frame or associated housing. Preferably, the stator bore walls and the rotor are concentrictor provide a uniform air gap between the parts; otherwise the motor will be inefficient and have unacceptable operating characteristics.
It is important that a DC brushless motor in actuator applications provides equal performance in both directions (same current, input power and speed), and this is achieved by locking the stator assembly into a tined position which prevents the stator assembly from moving axially or radially. One or two degrees of radial movement of the stator assembly relative to the housing after the commutator resolver is aligned, will cause as much as a ten percent increase in motor current and input power, along with a decrease in motor speed, resulting in an equal impact on the system's critical performance.
Heretofore, rather complex, costly and heavy locking fixtures, brackets or the like have been used to lock the motor stator assembly. To reduce such factors, locking pins or the like have been bored directly into the laminated body of the stator assembly, which is an undesirable approach.
This invention is directed to solving the above problems by providing a nique mount for a stator assembly, such as in a permanent magnet brushless DC motor.